Audio systems have been developed to detect reflected signals for various purposes. For example, the sound pressure and frequency of a loudspeaker output can be detected by a microphone, and this detected information can be used to adjust the loudspeaker output accordingly. In another example, a proximity sensor can be used to detect a nearby object and adjust loudspeaker output. In yet another example, reflected ultrasonic signals are used to calibrate a sound pressure level to maintain a predetermined level. In yet another example, an object detection system is used to change an alarm in response to detecting a nearby object, such as a person. However, none of these systems are used to gate (i.e. turn ON or OFF) a loudspeaker, and all of these systems depend on a single input parameter to adjust an audio their output.
Accordingly, there is a need for a technique to gate an ultrasonic emitter. It would also be beneficial if the control of this gating function could be better controlled using more than one input parameter.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.